System and method for operating a turbocharged engine

Abstract

A method includes substantially reducing specific fuel consumption and exhaust emissions of an engine by adjusting an exhaust flow from a set of predetermined cylinders among a plurality of cylinders of the engine through an exhaust gas recirculation system to an intake manifold, by adjusting a temperature of a cooler of the exhaust gas recirculation system, and by adjusting a fuel injection timing, in response to variance in a plurality of parameters of the engine.

Description

BACKGROUND[0001]The invention relates generally to a system and method for operating a turbo-charged compression-ignition engine and, specifically, to a system and method for substantially reducing specific fuel consumption and engine exhaust emission in a turbo-charged engine. More specifically, the invention relates to a system and method for enabling a uniform exhaust gas recirculation to different cylinders in a multicylinder engine.[0002]In a compression-ignition engine, such as a diesel engine, a fuel injection system injects fuel (e.g. diesel fuel) into compressed air within each of the engine cylinders to create an air-fuel mixture that ignites due to the heat and pressure of compression. Unfortunately, engine efficiency, power output, fuel consumption, exhaust emissions, and other operational characteristics are less than ideal. In addition, conventional techniques to improve one operational characteristic often worsen one or more other operational characteristic. For examp...

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Benefits of technology

[0006]In accordance with another exemplary embodiment of the present invention, a method for controlling a percentage of exhaust gas recirculation in a turbocharged system is disclosed. The method includes directing one portion of an exhaust flow from a set of predetermined cylinders among a plurality of cylinders of the engine through an exhaust gas recirculation system to an intake manifold of an engine. The method also includes directing another portion of the exhaust flow from the set of predetermined cylinders among the plurality of cylinders of the engine through an exhaust gas recirculation system to an exhaust manifold of the engine. The percentage of the other portion of the exhaust flow is controlled as a function of pressure ratio of a turboexpander of the exhaust gas recirculation system, speed of the turboexpander, or combinations thereof so as to substantially reducing specific fuel consumption and exhaust emissions of the engine.

[0007]In accordance with another exemplary embodiment of the present invention, a system having a controller configured to substantially reduce specific fuel consumption and exhaust emissions of an engine is disclosed.

Problems solved by technology

Unfortunately, engine efficiency, power output, fuel consumption, exhaust emissions, and other operational characteristics are less than ideal.

In addition, conventional techniques to improve one operational characteristic often worsen one or more other operational characteristic.

For example, attempts to decrease specific fuel consumption often cause increases in various exhaust emissions.

The usage of additional components for recirculation of exhaust gas increases specific fuel consumption (SFC) of the engine.

Also, conventional exhaust gas recirculation systems do not enable a uniform exhaust gas recirculation to different cylinders in a multicylinder engine.

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